Physical, biological, and cultural evolution span the spectrum of complexity, each comprising an essential part of the greater whole of cosmic evolution. Stars, planets, and life, as well as culture, society, and technology, all contribute to a magnificently coherent story of ourselves, our world, and our Universe. All these systems, among many other examples of order and organization in the richly endowed cosmos, share common features and common drives, thus comprising a common evolutionary epic.
The precise path of human evolution during the past few million years of the CULTURAL EPOCH is controversial in its details. The scientific data are sketchy, the historical record incomplete; specifics have been lost to the march of time. As best we know presently, modern humankind likely spread from Africa ~150,000 years ago—much as we are again today dispersing, however haltingly, while exploring the Solar System—but little is certain about the fossil remains or genetic diversity of our immediate forebears. What’s more, that which truly made us human involved the creative traits of emotion and imagination—qualities difficult to discern objectively. We have entered the realm of social studies, which is more slippery (in theoretical explanation), messier (in data acquisition), and indeed more complex (in subject matter) than any of the natural sciences. Understanding the tempo and mode of human evolution, including neural evolution of the brain, remains anthropology’s greatest challenge.
The causes of recent evolution include not only biological factors but cultural ones as well. An intricate biocultural interplay accompanied the increase in brain volume and the invention of technical skills, as well as the development of verbal communication and the onset of social organization, and not least the creation of subjective art and the discovery of objective inquiry. These changes were slow at first, but they have markedly accelerated within the past quarter-million years. Reduced to essentials, culture is the only difference between hunter-gatherers and ourselves. Cultural innovations (most notably perhaps the use and control of energy) have enabled Homo sapiens to become unprecedentedly complex as a life form on planet Earth. We alone can ask, moreover explore—religiously, philosophically, and scientifically—the fundamental questions regarding deep origins.
The matter networked within the human brain is among the most complex stuff in the known Universe. Many breakthroughs were needed along the road to intelligence, especially the ability of cells to cluster and interact starting ~1 billion years ago. More recently, tree swinging, manual dexterity, binocular vision, fire, tools, speech, writing, foresight, and curiosity, among many other evolutionary advances, all had a clear effect on the brain: It got bigger. Neurons have evolved steadily to the point where we now use them to steer our technological civilization, to unlock secrets of the Universe, and to reflect upon the material contents from which we arose.
Without a brainy seat of consciousness, galaxies would twirl and stars would shine, but no one would know it. Nothing could likely comprehend the majesty of the reality that is Nature. By contrast, with a conscious, curious brain, we probe the past and discovery our history, striving to decipher our celestial roots and the routes that brought us to the here and now, all the while searching for a better understanding of both the cosmos and ourselves. What emerges is nothing less than a cosmic-evolutionary heritage—a plenary worldview of who we are, whence we came, and how we fit into the universal scheme of all material things.
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Primate Information Network:
http://pin.primate.wisc.edu/Human Evolution:
http://www.becominghuman.orgArchaeology Net:
http://archnet.asu.edu/Stone Age Institute:
http://www.stoneageinstitute.org